<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>公共部分</title>
    <div th:fragment="header_common">
        这是th:fragment声明公共片段
    </div>

    <div id="header_common_id">
        <span>这是id选择器声明公共片段</span>
    </div>
</head>



</html>